toAppend support DoubleToStringConverter::SHORTEST_SINGLE (#928)
toAppend support DoubleToStringConverter::SHORTEST_SINGLE (#928)

Summary:
toAppend support DoubleToStringConverter::SHORTEST_SINGLE for float type.
Pull Request resolved: https://github.com/facebook/folly/pull/928

Reviewed By: yfeldblum

Differential Revision: D9790564

Pulled By: Orvid

fbshipit-source-id: b38d6542518aa0ed7f2b0e222e9870bb5f3a51e5

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly